85% Rule: What it means and why it matters
The 85% rule is a widely recommended towing safety guideline: your caravan's MTPLM should not exceed 85% of your car's kerbweight for confident, stable towing.
The 85% rule is not a law. It is a best-practice guideline promoted by The Caravan and Motorhome Club, the NCC (National Caravan Council), and most towing experts. It works like this: multiply your car's kerbweight by 0.85. If your caravan's MTPLM is below this figure, you should have stable, manageable towing in most conditions. Between 85% and 100% is technically legal but demands more experience, and the outfit becomes more susceptible to crosswinds and instability. Above 100% is not recommended by any expert. Novice towers should aim for 85% or below.
Why this matters
Matching ratio is the best predictor of towing stability. The 85% guideline gives you a safety margin for wind, wet roads, emergency braking, and driver fatigue.
Common misunderstandings
- The 85% rule is a guideline, not a law. You can legally tow up to your car's braked towing capacity
- The 85% figure uses kerbweight (car with fuel, no passengers). Not the car's actual weight when loaded
- Experienced towers can comfortably tow at 90-100%, but beginners should stay under 85%
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Frequently Asked Questions
No. It is a widely recommended safety guideline. The legal limit is your car's braked towing capacity, but staying under 85% provides a significant safety margin.
Multiply your car's kerbweight by 0.85. Compare this figure to your caravan's MTPLM. If the MTPLM is lower, you pass the 85% check.